1. Field of the Invention
The present invention relates to flat displays, more particularly to display panels, flat-panel display devices, and the driving method thereof.
2. Discussion of the Related Art
Demand for thinner, lighter, power-saving flat-panel display devices with enhanced visional effect has increased nowadays. The parameters relative to performance of the display devices includes contrast, brightness, viewing angel, response time, and so on. Among the above factors, brightness, winch is determined by the backlight source and the layout of driven chips, is the most important one.
Referring to FIGS. 1 and 2, the flat-panel display device includes a display panel 11, a printed circuit board 12, a source driven IC 13, a first gate driven IC 14 and a second gate driven IC 15. The printed circuit board 12 and the electrically connected source driven IC 13 are arranged in a lateral area vertical to data lines (not shown) of the display panel 11. The first gate driven IC 14 and the second gate driven IC 15 are arranged in a lateral area vertical to gate lines (not shown) of the display panel 11. With respect to the distance to the source driven IC 13, the first gate driven IC 14 is closer than the second gate driven IC 15. A third gate driven chip 16 and a forth gate driven chip 17 are symmetrically arranged in the lateral opposite to the first gate driven IC 14 and the second gate driven IC 15. Alternatively, the third gate driven chip 16 and the forth gate driven chip 17 may be arranged in the same lateral with the first gate driven IC 14 and the second gate driven IC 15.
The printed circuit board 12 provides gate driven signals (“VGH”) to the first gate driven IC 14 and the second gate driven IC 15 via leading wires 1 and 2. It can be seen that the VGH to the second gate driven IC 15 is not only transmitted by the leading wires 1 but also by the leading wires 2. The leading wires 2 include additional resistors and parasitic capacitors so that the amplitude and the waveform of the second gate driven IC 15 and the first gate driven IC 14 are different. Accordingly, as shown in FIG. 3, the amplitude and the waveform of the VGH input to the first gate driven IC 14 (see curve 21) and the second gate driven IC 15 (see curve 22) are different. In addition, the amplitude and the waveform of the output signals of the first gate driven IC 14 (see curve 23) and the second gate driven IC 15 (see curve 24) are different as shown in FIG. 4.
The brightness of display areas controlled by the first gate driven IC 14 and the second gate driven IC 15 are different as the amplitude and the waveform of the input and output signal of the first gate driven IC 14 and the second gate driven IC 15 are different. It can be understood that the brightness of the display area controlled by the second gate driven IC 15 is smaller that of the display area controlled by the first gate driven IC 14. In addition, as the gate lines of the display panel 11 are horizontal, the brightness of the display panel 11 is vertically distributed so that the visual effect of the display panel 11 is not good enough.